The development of haze in alcoholic and fruit beverages has long been a problem. Development of haze in beverages is undesirable from the viewpoint of product aesthetics and eye-appeal. In addition, haze development can result in loss of product color as well as taste. Solutions to this problem have been attempted by several different approaches. One of the commonly employed methods is reducing the temperatures of the beverage to 20-30° F. to cause haze formation. During such chilling, the haze precursors separate out as the so-called “haze” which can be then be separated using known techniques such as filtration. In many cases, such treatment by chilling is not completely effective, and several chilling and precipitation treatments are required. As an alternative to chill processing, attempts have been made to determine the amount of the precursors of haze in the grains employed in the production of specific beverages, e.g., by extraction of the malt employed in the production of beer. As a result of such determinations, grains of low haze-precursor content can be selected to produce beverages of low potential haze. Such procedures are costly and time-consuming. Although this approach can result in amelioration of the haze problem, it rarely can result in elimination of the haze problem.
It has long been recognized that the most frequent cause of haze in packaged beer is protein-polyphenol interaction (Compton, J. Beer quality and taste methodology. In the Practical Brewer, 2nd Ed. H. M. Broderick, Ed. Master Brewers Assoc. Am. Madison, Wis., pp. 288-308, 1977). Two basic approaches to stabilize beer, or at least to delay the onset of haze formation, have been developed: (a) reducing the concentration of the haze-active protein, or (b) reducing the concentration of the haze-active polyphenol. Haze-active polyphenol can be removed by adsorption with polyamide or polyvinylpolypyrrolidone (PVPP), or by fining. Haze-active proteins, but not foam-active proteins that form the foam in a beverage, can be removed by silica gel adsorption. The foam that is often present on a glass of beer or other beverage is considered a desirable quality of a beverage such as beer. The specificity of silica gel toward haze-active proteins occurs because silica gel binds to the proline residues in a protein; which are the same sites where polyphenols attach to create haze. (Siebert, et al., J. Am. Soc. Brew. Chem. 55: 73-38 (1997)).
In fruit beverages, the haze problem has been treated primarily through the use of enzymes, which hydrolyze the proteins normally forming haze with the phenolic components of the fruit preparation.
U.S. Pat. No. 3,958,023 discloses a method of treating a liquid derived from one or more vegetables or fruits to reduce the tendency of chill haze formation in said liquid, said method including a filtration step and the addition of one or more chill haze control agents, the improvement comprising including in a precoat or after precoat layer in the filter media used in said filtration step at least one chill haze control agent, and adding at least one chill haze control agent as body feed to said liquid prior to said filtration step, said chill haze control agents being selected from the group comprising hectorite, acid activated bentonite, acid treated acid activated bentonite, polyvinyl pyrrolidone, polyvinyl polypyrrolidone, natural magnesium silicates, synthetic metal silicates, and acid treated synthetic magnesium silicates containing less than 14 wt. percent MgO.
U.S. Pat. No. 4,282,261 discloses a process for removal of haze precursors from unstable beverages which comprises the step of contacting said beverage in a haze-free condition and at ambient temperature with a positive-charge modified porous medium comprised of fine particulate, the charge being modified with a polyamido-polyamine epichlorhydrin cationic resin, to form a precipitate and removing said precipitate from said beverage at ambient temperature.
U.S. Pat. No. 6,011,406 discloses a method for stabilizing a beverage containing haze-causing substances. The method comprises: (a) contacting a clarified beverage with a water-insoluble porous hydrophilic matrix to which ion exchanging groups are covalently bound, which is capable of adsorbing both haze forming proteins and polyphenolic compounds, and removing a portion, but not all, of the haze forming proteins and/or polyphenolic compounds; and (b) recovering the beverage from the matrix.
There is a need for an improved and less costly process that is suitable for preventing or reducing haze development in beverages. Such a system uses low-cost raw materials and is suitable for a large-scale production and requires no pretreatment of a sample.